I don't recognize the insects on your trees, but they appear they might be doing damage somewhat similar to a borer? If an old dead limb breaks off, do there appear to be tunnels leading through it?
I would get a hold of your county extension office and see if they could send someone out very soon to look at it.
If they can't get to you for weeks, maybe call a tree service about identifying what they are?
If that isn't possible, then perhaps get an insecticide to kill the active insects and buy yourself some time. I've been battling borers for a couple years (I appear to be finally winning), but they have done a lot of damage to two of my redbud trees...
I've been using a combination of Bayer Insect, Disease, & Mite Control spray and Bayer Tree & Shrub Protect & Feed liquid (basically a systemic liquid you pour around the tree base), and have had good results. A friend also started using the Protect & Feed over the last year for borers on one of her maples and she reports good results as well.
